Auto cut top of wall to slab over

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Hi All.

Ive recently moved from a practice with an excellent template to one with a poor template and Id like to update it but cant work out a few things.
In the previous template, where a slab was drawn above wall and that wall extended above the slabs home storey, the slab would automatically cut the wall, similar to SOE with Upwards Extrustion.

Id like to replicate this but cant work out for to do it. The Building Materials of the walls are weaker than the slab. The wall composite is made of 3 skins, brick, air, brick.
The slab is a strong Building Material of a single composite.

I hope this made sense. Can you guys help me out here?

Thanks.

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That fixed it!!

Absolute legend, thank you very much.